1. Field of the Invention
The present invention relates to a camera system including: a camera head which is provided with a photographic optical system and an image pickup device and is configured to generate image signals in accordance with given camera head data; and a camera body which is configured to fit the camera head interchangeably, to receive the image signals from the camera head, and to perform signal processing in accordance with given camera body data. The present invention also relates to the camera body constituting the camera system and to the camera head which is interchangeably fitted to the camera body.
2. Description of the Related Art
A camera system including: a camera head which is provided with a photographic optical system and an image pickup device and is configured to generate image signals in accordance with given camera head data; and a camera body which is configured to fit the camera head interchangeably, to receive the image signals from the camera head, and to perform signal processing in accordance with given camera body data, has been conceived in recent years. In this camera system, various grades of products ranging from a high grade to a low grade are assorted both in light of the camera head and in light of the camera body as appropriate, so that it is possible to combine any camera head selected easily with any camera body selected therefrom. By applying this configuration, it is possible to realize a camera system which meets any user's needs. Generally, in this camera system, the camera head includes a discrete central processing unit (CPU) and a storing section which stores a program containing given camera head data, and the camera body includes a discrete CPU and a storing section which stores a program containing given camera body data.
Here, some techniques for updating a camera program have been disclosed. For example, there is disclosed a technique configured to update a camera program by storing an extension file that affects an operation of a camera into a memory card which is detachably fitted to the camera in advance, and loading the file out of the memory card (see patent document 1: Japanese Patent Application Laid-open No. Hei 7(1995)-274060).
Meanwhile, there is disclosed a technique for updating a camera program by storing a program for realizing a camera function into an external storage medium in advance, then judging whether or not the program is compatible with a camera at the time of fitting the external storage medium to the camera, and transferring the program to the camera when the program is judged to be compatible with the camera (see patent document 2: Japanese Patent Application Laid-open No. Hei 10(1998)-224685).
Moreover, there is disclosed a technique configured to connect a camera to communication equipment such as a cellular telephone, to acquire information on a program for updating the camera from an external server through this communication equipment, and to update the camera based on the information (see patent document 3: Japanese Patent Application Laid-open No. 2002-252800).
Further, in a camera system designed for a camera body and a detachable lens barrel, there is disclosed a technique for updating a program for allowing the camera body to effectuate a function unique to the lens barrel by storing such a program into a storing section included in the lens barrel in advance, and transferring this program to the camera body (see patent document 4: Japanese Patent Application Laid-open No. 2003-107315).
Here, in terms of the camera system including the camera head and the camera body configured to fit the camera head interchangeably, there are the following problems when applying the techniques disclosed in the patent documents 1 and 2 for updating the program stored in the storing section of the camera head.
The technique disclosed in the patent document 1 is configured to update the camera program by fitting the memory card to the camera and then loading extension file that affects the operation of the camera. Meanwhile, the technique disclosed in the patent document 2 is configured to update the camera program when the program is judged to be compatible with the camera at the time of fitting the external storage medium to the camera. Accordingly, when the techniques disclosed in the patent document 1 or 2 is applied to the camera system, the program in the camera body may be updated but the program in the camera head cannot be updated. Here, it is also conceivable to provide the camera head with a slot for fitting the memory card or the external storage medium and to update the program in the camera head through this slot. However, it is unrealistic to provide the camera head with such a slot.
Meanwhile, in order to apply the technique disclosed in the patent document 3 to the camera system, it is necessary to provide digital interfaces for performing data transfer to and from the communication equipment such as a cellular telephone to both of the camera body and the camera head. Such a configuration brings redundancy to the camera system.
In addition, the technique disclosed in the patent document 4 is configured to update the program in the camera body for controlling the lens barrel by transferring the program for realizing the function unique to the lens barrel to the camera body. Accordingly, when this technique is applied to the camera system, the program in the camera body may be updated but the program in the camera head cannot be updated.